Fig. 4

AO fracture classification. (A2) Transtrochanteric comminuted fracture, medial, and posterior bone cortex comminuted in more than two planes, lateral cortex intact. (A2.1) One medial fracture. (A2.2) More than two medial fracture blocks. (A2.3) The fracture line extending more than 1 cm under the lesser trochanter